Create/Modify Spline

Ribbon menu Elements tab Data Elements container Create/Modify Spline
or
(Classic) Build Data Element Spline New/Modify
The Spline Editor provides a tabular or plot view of your spline data for editing and plotting. You can drag points on your spline plots and see the effect of different curve-fitting techniques on your spline. You can also select linear extrapolation and view its effect.
Using the Spline Editor, you can create a two- or three-dimensional splines. Note, however, that the Spline Editor does not display a three-dimensional spline in plot view.
To set the view of the Spline Editor:
Set View As to either Tabular Data or Plot.
 
Note:  
Large number of values pasted into user interface fields or data tables may result in application instability. MSC recommends users to enter no more than 1 million data points at a time.